The exercise lasted just 15 minutes, but it worked wonders. Those who wrote about their values had added 0.3 points to their grade point average by the end of the term, closing the academic gap between them and their white peers by 40 percent. After two years (and a few ‘booster’ repetitions of the same exercise), their GPAs were still higher by a quarter of a point.
The exercise worked, Cohen said, because it breaks a vicious and self-fulfilling psychological cycle. Black students have to worry about the negative stereotype that they underperform at school, and that worry causes so much stress that they actually do underperform—an insidious effect known as stereotype threat. By asking the children to write about their values, Cohen mentally vaccinated them by bolstering their sense of self-worth. According to this theory, only students who are subject to negative stereotypes should benefit, and the poorest performers should benefit most. And that’s exactly what the team found.
Cohen has since replicated his results in other schools. He and others, like Walton, have also tested similar exercises with other groups who suffer from negative stereotypes like women in college physics classes. Time and again, they found that these short, simple tasks could have dramatic, lasting benefits.
At first, so did Paul Hanselman from the University of California, Irvine. Like Gerber, he came from a place of open-minded interest. “Cohen’s original study looked exciting and promising,” he says. “It looked like a way of addressing these very large and troubling racial achievement gaps.”
In 2011, Hanselman and his colleagues repeated the study with 374 minority seventh-graders from 11 schools in a single Midwestern district, with the same materials that Cohen had used. This time, the black students gained just 0.065 GPA points—a much weaker effect than in the original study, but a positive one nonetheless, and one that also lasted for years. But Hanselman, wanting to make the most of his relationships with the school district, repeated the study a second time. “Life would be so much easier if we hadn’t,” he says.
This time, they went bigger, recruiting 449 minority children. And this time, they found that the writing exercise had no effect at all.
The critical thing here is that Hanselman has replicated both Cohen’s original experiment and his own successful replication—a rarity in psychology. This means the usual criticism—that the replicating team missed key aspects of the original experiment, as Bryan claims of Gerber—doesn’t quite apply. “We were the same team in the same schools with many of the same teachers and administrators, and there were a lot of subtleties that we controlled in our two trials,” says Hanselman.
“I was mostly impressed by the high quality of their methods,” says Linda Skitka from the University of Illinois at Chicago. “They have a very large sample size, they examined a range of possible contingencies for why the effect might be observed with some students but not others, and they conferred with the original authors and used their exact materials.” But despite those efforts, Hanselman is no closer to explaining why his two replications differed in their results. “A lot of the most obvious things don’t seem to explain the difference, which leaves us with a puzzle,” he says.